The present invention relates to a rear door structure of a vehicle, and more particularly, to a rear door structure of a vehicle including a safety beam overlapped with a door-side outer panel that can effectively absorb an impact force and protect the safety of occupants.
In general, doors are hinged onto a vehicle body to be opened or closed for the vehicle occupant to get in or out of the vehicle. The doors are classified into front and rear doors. A structure of the rear door 10, as shown in FIGS. 1 and 2, includes door outer panel 11 and door inner panel 12 with a predetermined gap with the frames; a door side outer panel 13 bent and formed with predetermined gap with the door inner panel 12; a window glass 15 rising and falling along a door frame 14 by operation of a regulator; and a safety beam 17 installed between the door outer panel 11 and door inner panel 12 along a horizontal axis of the rear door 10 with both ends thereof supported against the door inner panel 12 via a beam mounting bracket 16. Safety beam 17 is typically formed in a shape of cylindrical pipe having a predetermined thickness to protect passengers by reducing the impact force transferred to the rear door 10 when a vehicle is impacted onto its side.
In other words, when a vehicle is crashed into the lateral side of the rear door 10, the impact force thereof is transferred to the safety beam through the door outer panel 11. A part of the safety beam 17, where the crash impact is applied, reduces the impact force by being transformed and destructed toward the door inner panel 12. As a result, the impact is reduced by transformation and destruction of the safety beam 17 to prevent any severe injury.
However, one problem in the conventional structure of the rear door thus constructed in that both ends of the safety beam 17 are installed without overlapping a support jaw portion 13-1 of the door side outer panel 13 due to limitations in its size and shape. The safety beam is mounted only with a simple connection to the door inner panel 12 via a beam mounting bracket 16, so that the safety beam 17 can not effectively absorb a side impact force.
On the other hand, the safety beam 27 of the front door 20, as shown in FIG. 3, is installed with both ends thereof longitudinally, extensively overlapping a support jaw portion 23-1 of door side outer panel 23 and connected to a door inner panel 22 by a beam mounting bracket 26. The beam mounting bracket 26 simply connects the safety beam 27 to the door inner panel 22, not to directly absorb the impact force like the beam mounting bracket 16 of the rear door 10 described above.
However, when a side impact occurs, the safety beam 27 of the front door 20 thus constructed protects occupants by effectively absorbing or scattering most of the crash impact. This is because the safety beam 27 of the front door 20 has a structure with both ends thereof being longitudinally, extensively overlapping with the support jaw portion 23-1 of the door side outer panel 23.
The impact absorbing capability of the safety beam may be determined based not only on thickness or strength, but also the size of overlap with the support jaw portion of the door side outer panel, as shown in FIG. 3. Both ends of the safety beam 27 of the front door 20 are installed in the structure forming an overlap (C) with the support jaw portion 23-1 of the door side outer panel 23. On the other hand, both ends of the safety beam 17 of the rear door 10 are not overlapped with the support jaw portion 13-1 of the door side outer panel 13 adjacent the rear wheel housing (not shown) in the structure as shown in FIG. 2. Thus, the conventional safety beam 17 of the rear door 10 can not as effectively absorb or scatter the impact force.
The present invention provides a rear door structure of a vehicle that improves the impact absorbing or scattering capability of the safety beam, and protects the safety of vehicle occupants when the vehicle experiences side impact.
In a preferred embodiment of the present invention, there is provided a rear door structure of a vehicle comprising a safety beam, an extension beam and an impact transfer beam. The safety beam is longitudinally arranged along a vehicle body at a space between a door outer panel and a door inner panel with both ends thereof being supported against the door inner panel via a beam mounting bracket. The extension beam includes one end inserted into and coupled with the safety beam and the other end overlapped with the door inner panel and surface-coupled with a support jaw portion of the door outer panel at a predetermined length. The impact transfer beam is formed along a curved surface of a rear wheel housing with one side thereof coupled to the extension beam and the other side thereof coupled to the beam mounting bracket.
In an alternative embodiment of the invention, there is provided a rear door structure for a vehicle comprising inner and outer door panels which define a gap therebetween, and the inner panel defines a stepped portion. A safety beam is positioned horizontally within the door, and terminates short of the inner panel stepped portion. An extension beam extends from the safety beam and overlaps the inner panel stepped portion. A mounting bracket is interposed between the extension beam and inner door panel stepped portion, securing together the extension beam, safety beam and inner door panel. An impact transfer beam is mounted substantially vertically between the extension beam and inner door panel stepped portion, and is curved to at least substantially follow a contour of an associated rear wheel housing.
In a further preferred embodiment, the safety beam is a tubular member wherein an extension beam is inserted into an end of the tubular member. The mounting bracket overlaps the end of the tubular member and is angled inward to contact the extension beam adjacent an end of the extension beam opposite the tubular member.